The house fly (Musca domestica L.) enjoys a cosmopolitan distribution. The enormous potential that this species possesses for pathogen transmission is well documented (Greenberg 1973, Flies and disease. Vol. I. Princeton University Press, Princeton N.Y., 856 pp. and West & Peters 1973, An annotated bibliography of Musca domestica Linnaeus. Dawsons of Pall Mall, London, 743 pp.). In addition to transmitting disease, the house fly is a major pest in or around livestock, swine, and poultry facilities (West, L.S., 1951, The housefly. Comstock Publishing Company, Ithaca, N.Y., 584 pp.). Heavy fly populations not only can cause actual economic losses in production to various classes of livestock but also can cause other economic losses. For example, livestock production facilities may be cited as a nuisance to surrounding residents as a result of flies, odor, and dust with resulting fines, attorney fees and settlement costs. (Campbell 1993. "The economics of the fly problem," pp. 34-39. In G. D. Thomas & S. R. Skoda. [Eds.], Proceeding of a symposium: Rural flies in the urban environment? University of Nebraska-Lincoln, Res. Bull. 317, 97 pp.).
Insecticides have been used as the primary method for fly control for the last 100 years and are still widely employed today. In spite of the large numbers of chemical products available, heavy fly populations are still present at livestock installations and the flies can disperse into urban areas (Thomas & Skoda 1993. supra). Many house fly control failures have been attributed to insecticide resistance (Meyer et al. 1987 J. Econ. Entomol. 80:636-640, Scott & Georghiou 1985, J. Econ. Entomol. 78:319-326).
One of the alternative control methods for house flies is attractants which can be deployed in the domestic and feedlot environment. However, existing commercial house fly attractant baits have shown mixed results (Browne 1990. "The use of pheromones and other attractants in house fly control." pp. 531-537. In L. R. Ridgway, R. M. Silverstein & M. N. Inscoe [Eds.], Behavior-modifying chemicals for insect management. Marchel Dekker, Inc., 761 pp.). Studies on attractants for the house fly are not new and have focused on evaluating the attractancy of single compounds or complex odorant mixtures in olfactometers, small rooms, and the field (West & Peters 1973, supra and references therein). These studies have demonstrated that mixtures are more attractive than single chemicals (Brown et al. 1961. J. Econ. Entomol. 54:670-674), Mulla et al., 1977. J Econ. Entomol. 70:644-648, Kunast & Gunzrodt, 1981. Anz. Schadlingskde. Pflanzenschutz Umweltschutz 54:131-135). House flies can be attracted to single odor sources such as indole, 3-methylindole, or butanoic acid in the field (Brown et al. 1961, J Econ. Entomol. 54:670-674; Frishman & Matthysse 1966, "Olfactory responses of the face fly Musca autumnalis De Geer and the house fly Musca domestica Linn." In Memoirs Cornell University Agricultural Experiment Station, 496. Cornell University, Ithaca, N.Y.; and Mulla et al. 1977, supra). However, the most effective attractants for house flies appear to be natural products, and especially effective are the products of putrefaction and fermentation, the sources of which can serve as oviposition sites and food sources. Dairy products and sugar-containing substances also are considered effective attractants (Kunast & Gunzrodt 1981 supra). These sources are generally malodorous and are therefore not acceptable as commercial or residential fly attractants.
Manure and spilled feed are the principal breeding media for the house fly (Skoda & Thomas 1993. "Breeding sites of stable flies and house flies," p. 61-67. In G. D. Thomas & S. R. Skoda. [Eds.], Proceedings of a symposium: Rural flies in the urban environment? University of Nebraska-Lincoln, Res. Bull. 317, 97 pp.). Larsen et al. (1966. J Econ. Entomol. 59:610-615) demonstrated that odor taken from air that has passed through a mixture of water and pig manure was attractive to house flies in an olfactometer, and that of eight different types of manure tested, pig manure was the most favorable site for oviposition.
Considerable effort has been expended to identify the compounds emanating from livestock manure. In pig manure, at least 140 different volatile compounds and gasses have been identified (Yashuhara & Fuwa 1979. Agric. Biol. Chem. 43:313-316;, Spoelstra 1980, Agric. Environ. 5:241-260; Yashuhara et al. 1984, Agric. Biol. Chem. 48:3001-3010; O'Neill & Phillips 1992, J. Agric. Engng. Res. 53:23-50; and, Chen et al., 1994, Biosource Techn. 49:83-87).
Chemical attractants have been used to attract other insects. For example, Jones et al. and others identified a chemical attractant for the screwworm (Cochilomyia hominivorax), swormlure-4. This attractant is a synthetic blend of compounds derived from decomposing liver and includes 2-butanol, 2-methyl-2-propanol, dimethyl disulfide, acetic acid, butanoic acid, pentanoic acid, phenol, p-cresol, benzoic acid, and indole (J. Econ. Entomol. 69:389-391, 1976; Coppedge et al. 1977, Environ Entomol. 6:66-68; and, Mackley & Brown. 1984, J. Econ. Entomol 77:1264-1268). Research performed on nontarget insects attracted to an older formulation of swormlure-4, swormlure-2 (Coppedge et al. 1977, supra), showed that of the 168 collected insect species (totaling 4,640 insects), only 4% were in the family Muscidae of which the housefly is but one of hundreds of species (Peterson et al. 1981, Environ. Entomol. 10:511-516).
There is a paucity of literature regarding the actual volatile compounds in pig manure that are responsible for attracting house flies. Chemical attractants that are commercially available have met with only limited success. New chemical attractants are needed to control house fly infestation.